1. Field of the Invention
The present invention relates generally to the art of coverings for doors and windows and more particularly to the preparation of vanes which may be used for such door or window coverings. In its most preferred embodiment, the present invention relates to novel vane structures which include fabric coverings and foam cores. The present invention also relates to a method of making such foam core products.
2. Description of the Prior Art
A wide variety of coverings for doors and windows are known to the art. These include very old products such as roller shades and venetian-type blinds, as well as the newer types of "soft" window coverings including pleated and cellular blinds and shades, various light control products, and fabric covered vertical blinds. The latter typically include a track which extends across the opening to be covered, with trucks mounted in the track for movement by a wand device or by cords and pulleys. Vanes are attached to the truck and are pivotable about a longitudinal axis of the vanes to open them to a first position and thus permit light to enter a room and to pivot them to a second position in which the vanes overlie one another, in which case privacy is achieved.
Recently, a number of such vertical blind products have been proposed to include hollow fabric vanes, which can include stiffening compounds to insure that the bottom rotates the same amount as the top with no twist top to bottom to achieve an aesthetically pleasing product. Moreover, light weight fabrics have been attached to thin, rigid vanes to achieve a "blind with curtain" product, one of which is disclosed in U.S. Pat. No. 5,638,881 issued to Ruggles, et al. on Jun. 17, 1997 and entitled "BLIND WITH CURTAIN".
It has also been proposed that vanes for door and window coverings can be prepared in a tubular configuration, the cross-section of such vanes simulating an air foil. They are preferably made from material having diagonal, dimensional stability or memory so that they resist stretching in the longitudinal direction. It is also known that with such vanes, a reinforcing strip can be applied to an open end of the vane to provide a positive and durable attachment for supporting the vane from an operating system. One patent describing such vanes is U.S. Pat. No. 5,797,442, issued Aug. 25, 1998 to Colson, et al., for "Vanes For Architectural Covering and Method of Making Same".
The vanes used in the aforementioned Colson, et al. patent have a cross sectional configuration best illustrated in FIG. 6d of the patent, i.e., one resembling an air foil. Various techniques are described for insuring that the shape is maintained, such as the use of stiffening compounds, or in the embodiment shown in FIG. 12, the use of a resilient rubber strip along the inside of the vane, i.e. at the blunt end. Various single and double thickness vanes and further vane structures are also disclosed in PCT International Application WO96/35881, to the same inventor, which application claims priority to the parent application of the aforementioned '442 Colson, et al. patent.
FIG. 1 of the Colson, et al. patent discloses a vertical arrangement in which a plurality of the vanes are suspended from a track 30 and are pulled across the opening to be covered using a wand. The vanes may also be rotated to an open, light-admitting position as shown in FIG. 1, or to a privacy position, shown in FIG. 3. If the vane is constructed from transparent or sheer materials, light can be admitted in a diffused pattern into the room when in the closed position, as illustrated in FIG. 4 of this patent.
While new window coverings are shown in the PCT application and the issued Colson, et al. patent, a variety of different and useful door and window coverings employing foil shaped vanes are not disclosed or contemplated. Furthermore, while some thermal insulation benefits may be obtained by using hollow vanes, the amount of insulation is relatively modest. Moreover, the hollow vanes employing fabric are delicate and will quickly become damaged in more severe end use applications. A door or window covering which overcomes these and other disadvantages of the prior art door and window coverings would be a significant advance in this art.